ESC 23: STOPDAPT-3: Prasugrel Monotherapy Without Aspirin in Acute Coronary Syndrome Patients
Published: 26 Aug 2023
ESC 23 — Dr Masahiro Natsuaki (Saga University, JP) discusses the short and optimal duration of dual antiplatelet therapy-3 Study (STOPDAPT-3) (NCT04609111).
In the STOPDAPT-2 study, 1-month dual antiplatelet therapy (DAPT) followed by clopidogrel monotherapy was shown to provide benefits in bleeding reduction over a 12-month period, however, other trials have shown high rates of bleeding at one year in high bleeding risk (HBR) patients.
The STOPDAPT-3 Study (Kyoto University) aimed to explore the potential benefits of prasugrel monotherapy (without aspirin) when compared with 1-month of DAPT with aspirin and prasugrel in reducing bleeding events post-percutaneous coronary intervention (PCI) in HBR and acute coronary syndrome (ACS) patients.
6002 patients were enrolled in the trial, where major bleeding was defined as BARC criteria 3 or 5. Results suggested that prasugrel monotherapy did not attest superiority for the reduction of major bleeding events within 1 month after PCI, and was associated with an excess of coronary events including sub-acute stent thrombosis.
- What is the background to this trial?
- 2. What was the study design, patient population and outcome measures?
- What are the key results presented at ESC?
- What is the applicability to populations outside of Japan?
- What are the take-home messages?
- What are the next steps?
Recorded on-site at ESC Congress 2023, Amsterdam.
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Editors: Mirjam Boros and Jordan Rance
Video Specialists: Dan Brent, Tom Green, Mike Knight, Oliver Miles
"My name is Masashiro Natsaki from Saga University, Japan. I will present the results of STOPDAPT3 trial comparing the conventional DAPT strategy versus no aspirin strategy in patients with PCI.
Background of the Trial
DAPT is the standard strategy in patients undergoing PCI to prevent ischemic cardiovascular events, stent thrombosis in particular, at least one month after PCI. However, the incidence of major bleeding still remains high in patients with acute pulmonary syndrome or high bleeding risk. So in meta-analysis short durations of DAPT followed by a P2Y12 inhibitor monotherapy demonstrated 40% risk reduction in major bleeding events without increasing cardiovascular events. So the hypothesis of this study is that removing aspirin from DAPT regimen could reduce major bleeding events without increasing cardiovascular events in patients with ACS or HBR.
Study Design, Patient Population and Outcome Measures
66,000 patients with ACS or HBR undergoing PCI were randomly assigned to no aspirin group and DAPT group in one-to-one fashion.
The primary endpoint is bleeding and cardiovascular events. Regarding the Co-primary bleeding endpoint, cumulative one-month incidence was 1.5% in the no aspirin group and 4.7% in the DAPT group. Hazard ratio was 0.95, and p-value was 0.66, so no aspirin group was not superior to the DAPT group. Regarding the co-primary cardiovascular endpoint, evaluating the non-inferiority cumulative one-month incidence was 4.1% in the no aspirin group and 3.7% in the DAPT group. Hazard ratio was 1.12, and upper 95% confidence interval was less than 1.5. So no aspirin group was non-inferior to the DAPT group. However, the rate of sub-acute, definite or probable stent thrombosis and unplanned coronary revascularization was higher in the no-aspirin group than in the DAPT group.
Applicability to Populations Outside of Japan
We should be careful in adapting this result to the population outside Japan. First, risk profile is different from Japanese and Westerns. Second, we used the low dose prasugrel in this study and this dose is one-third of the global dose of prasugrel. So we should be careful in adapting this result to the population outside Japan.
In summary, aspirin-free strategy compared to the DAPT strategy failed to attest superiority for major bleeding event and was associated with a signal suggesting an excess of coronary events with no aspirin strategy. So DAPT with Aspirin and P2Y12 inhibitor would still remain the standard strategy in patients undergoing PCI at least within one month. Actually, the incidence of major bleeding was unacceptably high in this study, so further trials are needed. Exploring the strategy to reduce major bleeding events early after PCI in patients with ACS or HBR.”